The present invention relates sensing and detection of electrical or other characteristics associated with defective or unauthorized items in a supply chain using multiple detection and data system modalities. Defects or unauthorized status can include parts that do not conform to their specifications, are not authorized by an original equipment manufacturer, a case where a used part is being passed off as a new part, or a case where a part or component has been subjected to one or more damage or stress events exceeding acceptable limit such as electrostatic discharge (ESD) events. System defect or supply chain problem detection is increasingly more difficult given large volumes, difficulty in accessing parts in an assembly, and different sizes, shapes, and input/output structure, particularly for mass produced parts or defect detection for parts that have left a factory. Thus, there is a need to improve electronic system supply chain defect detection capabilities which can be used at any stage in a supply chain.
A common problem with existing methods of acquisition and comparison of parts in a supply chain is that they are generally not good at accounting for normal manufacturing process variations, which can vary with device lots and foundries. Existing methods also tend to focus on a single stress indicator, such as input/output (I/O) shift due to electrostatic discharge (ESD). Thus they do not represent comprehensive evaluation methods.
One embodiment of the invention uses multiple test detection and data collection/input modes coupled with one or more decision engines such as neural networks, image recognition, statistical correlation tools, and decision trees, which can incorporate various learning processes. Another embodiment can also include a data collection system with one embodiment including electromagnetic (EM) sensors and data collection inputs adapted to sense test data and input the data to an embodiment of the multiple mode analysis decision engine to evaluate a device under test (DUT) system. For example, an embodiment of the invention can incorporate integration of multiple EM sensors as well as data inputs and in synchronization with DUT stimulation for the purpose of producing device unique EM signatures accompanied by a decision engine, including a neural engine, to provide a variety of novel embodiments of the invention to meeting a variety of supply chain item defect or unauthorized item detection needs.
An exemplary embodiment can apply a decision engine to multiple electrical characteristic modalities data sets for the purpose of determining a probability that a microelectronic device is unauthorized, does not meet specification(s), or is defective. Inputs to an exemplary decision engine can include a variety of potential data sets that can be evaluated. The additional information obtained in applying multiple data sets in combination with a sensor system that can be used with a wide variety of DUTs, both in a factory and elsewhere, will allow a much more accurate probability assessment of DUTs. Testing systems can also use various methods for measuring different stressors that would indicate a part has, for example, been previously used or stressed (thus is unacceptable or does not meet specification(s)), such as experiencing an ESD damage event.
An exemplary stimulus could be applied in such a way as to produce device dependent signatures useful in determining a probability that a device has a defect, improper part installed, or has otherwise experienced environmental stress. An exemplary EM apparatus may include a positioning system, switch matrix, power combiner, switch and electromagnetic interference (EMI) shielding to minimize stray EMI signals. An exemplary embodiment can also combine various probe types, such as E-field, and H-field probes of varying bandwidths, as well as visual, infra-red, etc in an integrated manner.
Additional features and advantages of the present invention will become apparent to those skilled in the art upon consideration of the following detailed description of the illustrative embodiment exemplifying the best mode of carrying out the invention as presently perceived.